This invention relates to apparatus for checking the movement of a pivoted tool of a tunnel-driving machine, which tool is rotatably mounted on a pivoted cutter arm and freely movable over a breast, relative to a desired profile of the tunnel to be driven, wherein a focussed electromagnetic wave train, which is aligned with the axis of the tunnel, is used as well as a receiver mounted on the tunnel-driving machine. In known apparatus of that kind, one receiver or a plurality of receivers is or are fixed to the tunnel-driving machine and one laser beam or a plurality of laser beams is or are employed and it has been endeavored to obtain by trigonometric calculations a representation of the coordinates of the cutter head relative to the coordinates of a desired profile of the tunnel to be driven. Specifically, a laser beam receiver has already been proposed which comprises a number of light-sensitive elements distributed on a surface. These light-sensitive elements, which were relatively small, were preceded in the direction toward the transmitter by a template or another plate, which carried light sensitive elements. The detection of those light-sensitive elements which received the laser beam at a given time permitted a conclusion regarding the position of the tunnel-driving machine relative to the axis of the tunnel. The known system of that kind requires a high expenditure for calculation and owing to the large number of light sensitive elements required for the calculation is rather susceptible to trouble. This susceptibility to trouble is particularly due to the fact that the operation of the light-sensitive elements may be strongly affected by dust, shakes and high temperatures and that regulations issued by mining authorities permit only laser beams of very low intensity to be used in order to avoid firedamp explosions.